Anticholinergics may expediently be used therapeutically in a variety of complaints. Particular mention should be made here, for example, of the treatment of asthma or COPD (chronic obstructive pulmonary disease). For treating these diseases WO 92/16528 proposes for example anticholinergics which have a scopine, tropenol or tropine basic structure. WO 92/16528 also mentions methods of preparing these anticholinergics. Other methods of preparing esters of scopine are disclosed in EP 418 716 A1.
The scopine esters of general formula 1 are already known from WO 03/064419 A1. WO 03/064419 A1 also discloses methods of preparing the scopine esters of general formula 1.
Besides the methods of synthesis disclosed in WO 92/16528 for preparing scopine esters, methods of preparing esters of scopine are also disclosed for example in EP 418 716 A1. The preparation methods known from WO 92/16528 and EP 418 716 A1 and from WO 92/16528 may also be used to prepare the compounds of formula 1. However, these methods of synthesis are in some cases highly complex procedures made up of a number of synthesis steps.
The aim of the present invention is therefore to provide a method of synthesis for preparing the scopine esters according to formula 1, which allows easier synthesis of the compounds of general formula 1, preferably a one-step method of synthesis.